Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13
The human brain doesn't stop developing until about 25 years old.
102
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55